ES2333240T3 - ELECTROCHURGICAL GENERATOR AND SYSTEM. - Google Patents

Abstract

In an electrosurgical generator for generating radio frequency power, the generator comprises a radio frequency output stage having three or more output connections, one or more sources of output power coupled to the output stage, and a controller operable to cause the generator to supply a first cutting RF waveform to the output connections or a second coagulating RF waveform to the output connections. In a combined mode, the controller causes the generator to deliver both first and second RF waveforms, the controller including means for feeding the waveforms to the output connections such that the first RF waveform is delivered between a first pair of the output connections, and the second RF waveform is delivered between a second pair of the output connections. The combined mode is adjustable between various settings, each setting having a different proportion of the first and second RF waveforms. In response to a operator-actuated input signal, the controller causes the generator to supply an output waveform starting at a predetermined start setting, ending at a predetermined end setting, and changing between the start and end settings according to a predetermined progression.

Description

Electrosurgical generator and system.

This invention relates to a generator system electrosurgical, and an electrosurgical system comprising a generator and an electrosurgical instrument with two or more treatment electrodes These systems are used normally for cutting and / or coagulation of tissues in surgical interventions, especially in paroscopic surgery ("keyhole") or minimally invasive surgery, but also in laparoscopic surgery or "open" surgery.

The resource of having generators is known electrosurgical that provide different signals from radiofrequency for cutting and coagulation, and also to arrange a mixed signal in which the generator quickly alternates between signals for cutting and coagulation. Our US Patent No. 6 416 509 and also US Patent No. 3,885,559 to Judson, describe mixed signals of this type. The U.S. document 2003/163124 (Goble) discloses an electrosurgical system that includes a Electrosurgical instrument that has at least three electrodes. In a combined mode, the cut and coagulation waveforms are distributed simultaneously or constantly alternating between first and second output voltage threshold values to form a mixed signal The circuit system makes the waveform cutting is distributed between a first pair of electrodes, and that the coagulation waveform is distributed between a second pair of electrodes in mixed mode.

According to the present invention, a system electrosurgical generator to generate power from radio frequency, includes:

(i)

a radio frequency output stage that has three or more output connections,

(ii)

one or more output power sources of radio frequency coupled to the output stage,

(iii)

an operating driver to cause the system supply power in a combined mode in which they are distributed a first cut-off RF waveform and a second Coagulation RF waveform to the output connections, including the controller means to feed the waveforms to the output connections so that the first waveform of RF is distributed between a first pair of output connections, and the second RF waveform is distributed between a second pair of output connections,

the system arrangement being such that the Combined mode is adjustable between various settings, having each configuration a different proportion of the first and second RF waveforms, and such that, in response to an input signal activated by operator, the controller causes the system supply an output waveform sequence that begins at a default initial configuration, ends in a default final settings, and switch between initial and final settings according to an evolution default

Our pending European patent application EP 1 287 788 describes an electrosurgical system in which the operator can select between a cut signal and a signal of coagulation. When the cut signal is selected, this is supplied to a pair of electrosurgical electrodes, and when it is selected the coagulation signal is supplied to a pair different from electrosurgical electrodes. Our request US patent pending US2003-0163124 is a improvement over this system, since it also provides a combined mode of operation, but being the different components of the combined signal supplied to different sets of electrosurgical electrodes. The present invention provides another improvement in which the waveform sequence output evolves from a default initial configuration up to a final default configuration.

The evolution of the waveform sequence It offers several advantages to the user. When an instrument electrosurgical is being used to cut tissue, in particular thick tissue, it is difficult to completely clot the tissue before the cut begins. If one is carried out prolonged coagulation before the cut begins, there is risk that some parts of the tissue are dehydrated. He dehydrated tissue is poorly receptive to RF energy, and so both an applied cut-off waveform will not be effective later. Conversely, if coagulation is incomplete, there is a risk of bleeding during the cut. Therefore, surgeons tend to repeatedly switch between the coagulation and cutting modes of the generators electrosurgical, as hemorrhages form (which makes Repeated actuation of the foot switch is necessary or Similary). The generator described in this application maintains a coagulation element during the entire cutting process, with a different proportion of the cut and coagulation waveforms as tissue treatment progresses.

Preferably, the first RF waveform shear is a waveform in which the output voltage of radio frequency developed through the output connections is limited to at least a first predetermined threshold value for cutting or vaporizing tissue, and the second form of Coagulation RF wave is a waveform in which the voltage Radio frequency output developed through the connections output is limited to a second threshold value for coagulation.

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The "combined mode" of the generator can be arranged in different ways. In a configuration, the system generator comprises a single source of radio frequency power and, in combined mode, the controller is operational to make the generator system alternates constantly between the distribution of the first cut-off RF waveform and the second form of Coagulation RF wave. This is the "mixed" signal more Traditional US Patent Nos. 6 416 509 and 3 885 569. Alternatively, the generator system comprises at least one first and second sources of radio frequency power, which they work at different frequencies, being the first source of radio frequency power adapted to distribute the first RF waveform cut, and being the second source of radio frequency power adapted to distribute the second Coagulation RF waveform and, in combined mode, the controller is operational to cause the generator system simultaneously supply the first and second waveforms of RF This is a different provision in which the output of Two RF sources are supplied to the instrument simultaneously. However, both provisions have the effect of providing RF signals from both cutting and coagulation to the instrument electrosurgical, while the instrument is in use.

In a preferred arrangement, the various configurations have a first default duty cycle of the first RF waveform, and a second duty cycle Default of the second RF waveform. Preferably the initial default configuration has a combination of waveforms such that the proportion of the second waveform of RF is greater than the proportion of the first RF waveform. Additionally, the default final configuration has a combination of waveforms such that the proportion of the first RF waveform is greater than the proportion of the second form RF wave Advantageously, the initial configuration is a way wave that has a second duty cycle that is between 70% and 100% of the total waveform, typically between 90% and 100% of The total output supplied. Alternatively or additionally, the final configuration is a waveform that has a first cycle of work that is between 70% and 100% of the waveform total, typically between 90% and 100% of total output supplied In a typical arrangement, the initial configuration is a combined waveform that has a first duty cycle that It is 100% of the total output supplied, and the final configuration it is a mixed waveform that has a second duty cycle that It is 90% of the total output supplied.

In the arrangement described above, no only the generator maintains a coagulation element during The whole cutting process, but the proportion of the waveform Coagulation is greater towards the beginning of the process. In this way, if the surgeon finds bleeding during the cut electrosurgical, the surgeon releases and then reactivates the footswitch or other drive mechanism. This reinitializes the evolution to the initial configuration, with a degree of coagulation in this proportionally high.

Preferably, the predetermined evolution from initial configuration to final configuration is a uniform evolution for a predetermined time. This ensures that the electrosurgical tissue cut will occur as soon as feasible to do it. Alternatively, evolution can not be a uniform evolution; but, for example, you can have a initial period in a constant configuration (for example, a predominantly coagulation waveform), followed by a evolution after this initial period until the final configuration (for example, a predominantly shear waveform). Regardless of whether evolution is uniform, time adopted by the generator to evolve from its configuration initial until its final configuration can be modified, depending on the type of instrument connected to the generator, or the type of tissue being treated.

Preferably, the controller is adapted to supply a total sequence of output waveform, in the shape of a series of impulses, conveniently at a frequency between 0.5 and 50 Hz, and typically at a frequency between 15 and 25 Hz

A system is described below. electrosurgical which includes an electrosurgical generating apparatus to generate radio frequency power, and an instrument electrosurgical that includes at least three electrodes, comprising the generating apparatus

(i)

a radio frequency output stage that has for at least two connections in electrical communication with the electrodes of the instrument,

(ii)

a power supply coupled to the stage of output to supply power to the output stage,

(iii)

an operating driver to cause the generator set provide a mixed output waveform that constantly alternate between a first output waveform at through the output connections where the output voltage of radiofrequency developed through the output connections is limited to at least a first predetermined threshold value for cutting or vaporizing tissue, and a second form of output wave through the output connections

in which the output voltage of radio frequency developed through the output connections is limited to a second threshold value for coagulation, including the controller means to feed the waveforms to the output connections so that the first waveform of output is supplied between a first pair of the connections of output, and the second output waveform is supplied between a second pair of the output connections, the controller being capable of causing the generating apparatus to distribute the form of wave in different configurations, having each of the different configurations a first predetermined duty cycle of the waveform that is limited to the first threshold value for cutting or vaporization, and a second predetermined duty cycle of the waveform that is limited to the second threshold value for the coagulation, the system arrangement being such that, in response to an input signal activated by an operator, the controller causes the generating apparatus to provide a sequence of the output waveform that begins in an initial configuration default, ending in a final configuration default, and switching between the initial settings and final according to a predetermined evolution. At least two of the Electrodes are shaped like a pair of jaws.

Accordingly, the invention extends to a electrosurgical system comprising

(i)

a bipolar electrosurgical instrument that includes a handle, a set of jaws arranged so that handle manipulation allows opposite jaws of the set of jaws open and close one with respect to other; having the first of the mentioned jaws opposed by at least a first coagulation electrode; having the other one of the mentioned opposite jaws at least a second electrode of coagulation; and a cutting electrode, the cutting electrode being separated from the second coagulation electrode by means of a insulating element, and

(iii)

an electrosurgical generating apparatus comprising one or more RF output power sources, a controller operational to control the generator set so that it can provide a first cut-off RF waveform to the instrument electrosurgical or a second coagulation RF waveform to the electrosurgical instrument and, in a combined mode, provide both first and second RF waveforms, being fed the waveforms to the electrosurgical instrument of so that, in the combined mode, the cut-off RF waveform is supplied between the cutting electrode and at least one of the first and second coagulation electrodes, and the waveform of Coagulation RF is supplied between the first and second coagulation electrodes, the combined mode being adjustable between different configurations, each configuration having a proportion different from the first and second RF waveforms, being the arrangement of the generating apparatus such that, in response to a signal operator-driven input, the controller causes the generator set supply a waveform sequence of output that begins in a default initial configuration, ending in a default final configuration, and changing between the initial and final settings according to a default evolution.

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The operation of the preferred system for modify tissue comprises the steps of:

(i)

put the tissue in contact with an instrument electrosurgical, which includes at least first and second electrodes

(ii)

supply the first and second electrodes a combination of electrosurgical waveforms that includes a first proportion comprising a cut-off RF waveform and a second proportion comprising an RF waveform of coagulation, and

(iii)

vary the proportions of the first and second waveforms, according to a predetermined evolution.

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The invention will be described in greater detail at then, by way of example only, with reference to the drawings annexes In the drawings:

Figure 1 is a schematic representation of an electrosurgical system, according to the present invention,

Figure 2 is a block diagram of the generator of figure 1,

Figure 3 is a schematic view in perspective of an electrosurgical instrument used as part of the system of figure 1,

Figure 4 is a schematic of a circuit of switching used in the system of figure 1,

Figures 5A and 5B are circuit diagrams of two electronic switching devices for the circuit switching of figure 4,

Figure 6 is a schematic of one embodiment. switching circuit alternative that can be used in the system of figure 1,

Figure 7 is a block diagram of a generator, according to figure 2, which incorporates a circuit of switching according to figure 4,

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Figures 8A through 8C are schemes that show techniques for adjusting a mixed switching ratio, Figures 8A to 8C being circuit diagrams of devices alternatives for adjusting the ratio and figure 8B being a waveform diagram showing the operation of the device of figure 8A,

Figure 9 is a block diagram of a alternative embodiment of the generator system, according to the present invention,

Figure 10 is a block diagram of another alternative system, according to the invention,

Figures 11A and 11B are other systems Alternatives to feed cutting and coagulation outputs automatically to different pairs of respective electrodes,

Figures 12 and 13 are block diagrams of other alternative systems, according to the invention,

Figures 14A and 14B are diagrams of shapes of wave that show different mixed waveforms that can be produced by a generator according to the invention,

Figure 15 is a schematic view of a footswitch used as part of a system electrosurgical, according to the present invention,

Figures 16 and 17 are diagrams showing the generator setting according to the invention,

Figure 18 is a schematic sectional view. of an alternative electrosurgical instrument used as part of the system of figure 1,

Figure 19 is a perspective view of a jaw assembly of the instrument of figure 18,

Figure 20 is a cross-sectional view. of the body of the instrument figure 18,

Figure 21 is a view from one end of the set of jaws of figure 19, and

Figure 22 is a side view of the assembly of jaws of figure 19.

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Referring to figure 1, a generator (10) It has a female socket (10S) output that provides an output of radio frequency (RF) for an instrument (12) by means of a connection cable (14). Generator activation can lead to out from the instrument (12) through a cable connection (14) or by means of a switching pedal unit (16), such as shown, connected to the rear of the generator by a connection cable (18) of the switching pedal. In the embodiment shown, the unit (16) of the switching pedal has two pedals (16A) and (16B) to select a coagulation mode and a generator cut mode, respectively. Front panel The generator has buttons (20) and (22) to configure respectively coagulation and cutting power levels, which are indicated on a screen (24). The buttons (26) are arranged as an alternative means for selection between modes of coagulation and cutting.

Referring to figure 2, the generator comprises a radio frequency (RF) power oscillator (60) that It has a pair of output lines (60C) to attach to the instrument (12). The instrument (12) is shown in Figure 2 in the form of an electric charge (64). Power is supplied to the oscillator (60) via a power supply (66) in switched mode. In the preferred embodiment, the RF oscillator (60) operates at about 400 kHz, any frequency of 300 kHz and higher being viable, in the HF range. Switching mode power supply works typically at a frequency in the range of 25 to 50 kHz. Through the output line (60C) is coupled a threshold detector (68) of voltage, which has a first output (68A) coupled to the source of power supply (16) in switched mode and a second output (68B) coupled to a "activated" time control circuit (70). A microprocessor controller (72) coupled to the controls and to the operator screen (shown in figure 1) is connected to a control input (66A) of the power supply (66) for adjust the generator output power by supplying voltage variation, and to a threshold adjustment input (68C) of the voltage threshold detector (68), to set the limits of the maximum RF output voltage.

In operation, the controller (72) of the microprocessor causes power to be applied to the source of power (66) in switched mode when power is demanded electrosurgical by the surgeon activating a device activation switching that may be arranged in a handle or on a switching pedal (see figure 1). A constant output voltage threshold is set independently in the supply voltage through the input (68C), of according to the control settings on the front panel of the generator (see figure 1). Typically, for dehydration or coagulation the threshold is set to a dehydration threshold value between 150 volts and 200 volts. When you need an exit from cut or vaporization, then the threshold is set to a value in the range between 250 or 300 volts and 600 volts. These values of Tension are maximum values. That they are maximum values means that for dehydration at least it is preferable to have a form of RF wave output from low crest factor to provide the maximum power before the voltage is restricted to values provided. Typically a peak factor of 1.5 or less. When a combined mode output is needed, the voltage Output adjusted through input (68C) alternates constantly between the value for dehydration or coagulation and the value for cutting or vaporization, to create a waveform mixed.

When the generator is activated first, the status of the control input (601) of the RF oscillator (60) (which is connected to the time control circuit (70) "activated") is "activated", so that the device power switching that forms the oscillating element of the Oscillator (60) is connected during a maximum driving period in each swing cycle. The power delivered to the load (64) depends in part on the supply voltage applied to the oscillator RF (60) from the power supply (66) in switched mode, and in part of the load impedance (64). The threshold voltage for a dehydration output is configured to cause the sending of activation signals to the time control circuit (70) "activated" and to the power supply (66) in switched mode when the voltage threshold is reached. The control circuit (70) of the "activated" time has the effect of reducing virtually "device" activated time RF oscillator switching. Simultaneously, the source of switching mode power is disabled, so that the voltage supplied to the oscillator (60) begins to fall. He generator operation in this way is described in detail in Our European Patent Application Number 075443.

Figure 3 shows a possible design for the electrosurgical instrument (12). The instrument (12) comprises an axis (5) of the instrument at the end of which is a electrode assembly generally shown as (8). The set of electrode (8) comprises a central cutting electrode (2) arranged between two coagulation electrodes (3) and (40) larger. The layer of insulation (4) separates the cutting electrode (2) from the first coagulation electrode (3) while an insulating layer (41) separates the cutting electrode (2) from the second electrode of coagulation (40). The cutting electrode (2) protrudes slightly on the two coagulation electrodes.

When the user tries to make the instrument woven cut, the generator applies an RF waveform between the cutting electrode (2) and one or both coagulation electrodes (3) and (40). Conversely, when the user tries to make the instrument coagulate tissue, the generator applies an RF waveform of coagulation between the two coagulation electrodes (3) and (40). The Application of the mixed RF waveform will be described with reference to the switching circuit shown in figure 4.

Figure 4 shows a switching circuit generally indicated in (45) and comprising input connections (46) and (47) connected respectively to the two output lines (60C) of the generator (10). The switching circuit (45) has three output connections (48), (49) and (50). The output connection (48) is connected to the cutting electrode (2) in the device of the Figure 3. The output connections (49) and (50) are respectively connected to the coagulation electrodes (3) and (40) in the device of figure 3. An electronic device of switching (51) is connected between the output connections (48) and (49). The switch (51) can quickly make and interrupt the connection between the output lines (48) and (49). A condenser (53) is connected between the output connections (49) and (50), the capacitor typically having a value between 1 and 10 nF.

When the user activates the pedals (16A) or (16B) to operate the instrument (12) in mixed mode, the generator supplies alternative bursts of RF waveforms from cutting and coagulation to the input connections (46) and (47). He switching device (51) works synchronized with the shapes alternating RF waveform so that when you receive the part of the waveform that contains the cut waveform, the device switching opens so that there is an open circuit between the output connections (48) and (49). In this way the waveform RF cutting is supplied between the cutting electrode (2) and the coagulation electrode (40), through output connections (48) and (50) respectively. Conversely, when the part of the form wave that contains the coagulation voltage is received through the input connections (46) and (47), the switching device (51) is closed so that the output connections (48) and (49) They are in electrical communication with each other. Thus, during the coagulation part of the mixed waveform, the waveform is supplied between two coagulation electrodes (3) and (40), to through the output connections (49) and (50), providing the capacitor (53) a potential difference between the two.

The switching device (51) can comprise an AC optical relay such as the dual FET arrangement optically coupled, shown in Figure 5A. Other device of switching that provides isolation between the circuits of control and the starting line is the combination of a bridge of alternating current and a single MOSFET switch controlled through an isolation controller, as shown in the figure 5B.

The above description is based on the generator (10) controlling the mixed mode waveform, and the switching device (51) opening and closing so synchronized with this. However, this does not have to be the case and the switching device can control the generator to determine the change between the cut-off RF waveforms and of coagulation

The circuit of switching (45) shown in figure 4. When the switching device (51) is in its open situation, the Cut-off waveform is supplied through the connections of output (48) and (50). When the switching device (51) is close, the cut-off waveform is initially supplied between the output connections (49) and (50), separated by the capacitor (53). This causes the current supplied by the generator increase rapidly so that the circuitry of current limitation within the generator work for reduce the power being supplied, so that the waveform quickly becomes a typical waveform of RF for coagulation. The effect of the circuit system of current limitation within the generator is that the closing of the switching device (51) causes the waveform to It is being supplied almost instantly, moving from a cut waveform to a waveform of coagulation. Conversely, when the switching device (51) reopens, the generator is no longer limited in current, and once again the waveform quickly becomes a form of RF wave cut. In this way, the opening and closing of the switching device (51) alternates the generator between their cutting and coagulation modes, producing the mixed waveform which is supplied to the electrodes of the instrument (12).

Figure 6 shows an alternative embodiment of the switching circuit, which can be used if the generator (10) is not a current limited generator, or if it is desired not to use the current limiting characteristics of the generator. The switching circuit of Figure 6 is almost identical to that of Figure 4, the main difference being the addition of an additional capacitor (52) in series with the input connection (46). The capacitor (52) typically has a value that is half the value of the capacitor (53), so that the voltage supplied through the output connections (49) and (50) is reduced to a level typically used for coagulation without reducing the power output of the generator (10). In this way, a cut-off RF waveform is supplied between the output connections (48) and (50) when the switching device (51) is open, and a waveform is supplied
Coagulation RF between the output connections (49) and (50) when the switching device is closed.

The switching device (45) can be disposed within the electrosurgical instrument (12), or inside of the generator output stage (10) as shown in the Figure 7. Wherever the circuit is located switching (45), this may be provided with a device adjustment (55), (as shown in figure 6) manageable by the system user to adjust the device timing of commutation. By operating the adjustment device (55), the user can alter the relationship between the part of the waveform of mixed RF which is a cut-off waveform, and the part that is a coagulation waveform. Be the adjusting device (55) located in the instrument (12) or in the generator (10), the user of the system can vary the waveform to increase or decrease the coagulation component of the mixed waveform with respect to the cutting component, and vice versa. This provides a considerable flexibility to the electrosurgical system in terms of its use as a simultaneous cutting device and coagulation, with user-manageable control over how much coagulation is provided.

As in the described arrangement previously in figure 4, the switching device (51) of the Alternative switching circuit of Figure 6 can be such as shown in figure 5A or figure 5B, obtaining the excitation signal from a source associated with the own switching device or from a circuit system of control inside the generator, which controls other functions of the generator.

For those skilled in the art they will be obvious several circuits to implement the adjustment device (55). In Figure 8A shows an example of a circuit in which it is generated a mixed mode waveform by means of elements associated with the switching device and has a relationship work-rest variable. In this case, the output of a triangular wave generator (56) is compared in a comparator (57) with a reference voltage adjustable by the user to produce a square wave of the device (51) of switching (figure 6). Figure 8C shows another circuit that generates a control signal of the switching device in mode mixed, adjustable. In this case, a potentiometer (58) can be activated by the user is coupled with a timer circuit (59) using an i.c. ("integrated circuit") 555.

Figure 9 shows a generator system alternative in which two RF source circuits are used (74) and (74 '). The source circuit (74) comprises the RF oscillator (60) and its associated power supply and control elements. He source circuit is as described in relation to figure 2, and the same elements receive the same reference numbers as in figure 2. The second source circuit (74 ') comprises a second RF oscillator (60 '), together with a second controller (72 '), a power supply (66'), a threshold detector (68 ') voltage and a time control circuit (70 '). Figure 9 shows the source circuit (74 ') with its own dedicated version of each of these units, although it is feasible that part of these (such as the power supply -66'- and the controller -72'-) can be shared with the source circuit (74). The detector (68) of voltage threshold is configured so that the connections of output (60C) from the source circuit (74) provide a output power waveform that has a waveform of RF cut-off, while the voltage threshold detector (68 ') is configured so that the output connections (60C ') from source circuit (74 ') provide a waveform of output power that has an RF waveform of coagulation. The second oscillator (60 ') operates at a frequency different from the oscillator (60).

A common output stage (73) is provided for both source circuits (74) and (74 '). The output connections (60C) from the source circuit (74) are connected to connections input (46) and (47) of the output stage (73), while the output connections (60C ') from source circuit (74') are connected to input connections (46 ') and (47') of the stage output, respectively. Within the exit stage (73), the input connections (47) and (47 ') are both connected to the output connection (49), while the input connection (46) is connected to the output connection (48), and the connection of input (46 ') to the output connection (50). The result of this provision is that the cut-off RF waveform coming from the source circuit (74) is supplied between output connections (48) and (49) and therefore to a pair of electrodes of the instrument electrosurgical (12). Simultaneously, the RF waveform of coagulation from the source circuit (74 ') is supplied between output connections (49) and (50) and therefore a couple different from electrodes of the instrument (12). In this way, the Electrosurgical instrument (12) can cut and coagulate tissue simultaneously under two frequency waveforms different. As before, the advantage is that the form of cutoff waveform and coagulation waveform, whether applied simultaneously or in an alternating mixed waveform, they are supplied to different pairs of instrument electrodes electrosurgical Therefore, the design of these electrodes can be optimized, as planned to cut or coagulate tissue.

Referring to figure 10, in another alternative combination of generator and instrument, two oscillators RF power (60-1) and (60-2) they are excited from a common power supply (62) and controlled by a common controller (72) to produce on the respective output lines (60C) a power waveform of RF suitable for cutting and an RF power waveform suitable for coagulation. These waveforms can be fed to a switching circuit (63) to select the power signal from the oscillator (60-1) or of the other oscillator (60-2), depending on the inputs from, for example, foot switches, being the selected power waveform transmitted over output connections (80), (81). In a mixed mode, the switch is repeatedly activated at a predetermined speed to produce a mixed output power waveform across the connections (80), (81). Power oscillators (60-1), (60-2) are activated at different frequencies, and the respective cut-off waveforms and of coagulation are fed to the required electrodes feeding the power waveform over output connections (80), (81) to tuned circuits (82-1) and (82-2), tuned to different frequencies. The outputs of the tuned circuits are coupled, through lines (48), (49) and (50) of electrode, to respective electrodes of the electrosurgical instrument Thus, the waveform of cut from the oscillator (60-1) is fed to the cutting electrode (48) and to the common electrode (49), while the coagulation waveform from the oscillator (60-2) is fed to a coagulation electrode (50) and to the common electrode (49).

In the embodiment shown in Figure 10, the connection between the electrosurgical generator and the instrument electrosurgical is typically arranged by means of output connections (80) and (81), but the distribution of circuit blocks between the generator and the instrument can be to vary.

Other figures are shown in Figures 11A and 11B realizations As in the embodiment of Figure 9, you are embodiments ignore the need for a switch or a signal routing switching circuit.

Referring to figure 11, two are arranged tuned circuits (82-1) and (82-2) (as in Figure 10), tuned to different frequencies Everyone has a pair inductor-capacitor (84) resonant in series and a inductor-capacitor pair (86) resonant in parallel, the last being coupled by transformer to output connections (46) and (47) on the one hand and (46 ') and (47') on the other hand. Like In the embodiment of Figure 10, each tuned circuit has two inputs, one of which is connected to a connection (80) generator output and the other one of which is connected to a  connection (81) of generator output. In this embodiment, the generator has an output stage comprising RF switches arranged in two pairs in counter phase (90A), (90B) and (91A), (91B) that act in the opposite way. Typically, these switches They comprise power MOSFETs. Each switch (90A), (90B), (91A), (91B) is connected to controller inputs (92), (93), such as it is shown, that they receive an RF excitation signal that, for produce on the output connections (80), (81) an output that have a cut-off waveform has a certain RF frequency, and to produce a coagulation outlet at the connections (80), (81) output, has a different RF frequency, these being frequencies, respectively, the resonant frequency of the resonant combinations (84), (86) of the first tuned circuit (82-1), and the resonant frequency of corresponding resonant combinations of the other circuit tuned (82-2). As described previously, the RF switches (90A), (90B), (91A) and (91B) of The generator output stage can be controlled according with, for example, a pedal switch control to produce a cutting outlet or a coagulation outlet. Again, additionally, a mixed output can be produced in which the RF frequency constantly alternates between the two frequencies Resonant tuned output circuits.

The embodiment of Figure 11B is a modification of the embodiment of figure 11A, in which the stage Generator output has a single pair of RF switches (90A), (90B) in contraphase and in which each of the circuits tuned has an input connected to the connection between the switches (90A), (90B) and the other input connected to ground.

Another embodiment of the generator circuit, in which the cutting and coagulation outputs are connected in series through the circuit system of commutation. The input connections (131) and (132) are connected to the generator output, and the output connections (133) and (134) to the instrument coagulation electrodes electrosurgical (12). The output connection (135) is connected to the cutting electrode of the electrosurgical instrument (12).

Between the input connections (131) and (132) there is a bridge circuit comprising a first transformer (136) and a second transformer (137). The first transformer (136) comprises a primary winding (138) and a secondary winding (139). A first switching element (140) is arranged in parallel with the primary winding (138). The second transformer (137) comprises a primary winding (141) and a secondary winding (142). A second switching element (143) is arranged in parallel with the primary winding (141). The elements of switching (140) and (143) are controlled by the control unit (144). The secondary windings (139) and (142) are connected in series through the input connections (131) and (132), constituting the connection between the two windings (139), (142) a bridge departure.

The second transformer (137) is a reducing transformer in which the secondary winding itself (142) It is the primary for another secondary winding (145), with socket central, connected through the output connections (133) and (134). An isolation capacitor (146) is disposed between the bridge circuit and connection (135) cut-off output, and others insulation capacitors (147) and (148) are between the bridge circuit and connections (133) and (134) output of coagulation.

The operation of the circuit is as follows. During a predetermined period, the control unit (144) activates the switching element (143) to close and short-circuit the primary winding (141) of the second transformer (137). In this situation, with the secondary transformer (141) effectively shorted, the generator output is directed between the output connection (135) and both output connections (133) and (134). This has the effect of exciting the cutting electrode of the electrosurgical instrument (12) with an RF output voltage with respect to the coagulation electrodes thereof, which effectively act as return electrodes for the operation of electrosurgical cutting

At the end of the predetermined period, the control unit (144) works to open the switch (143) and to then close the switch (140) to short-circuit the primary winding (138) of the first transformer (136). There's a default short delay between switch opening (143) and closing the switch (140) to ensure that both switches are never closed at the same time (since this short circuit generator output connections). With the switch (140) closed, the first transformer (136) is effectively shorted, and the generator output is directed completely to the second transformer (137). The second transformer is a reducing transformer, and provides a signal of lower voltage between the output connections (133) and (134). This it has the effect of exciting the first and second electrodes of coagulation of the electrosurgical instrument (12) to produce this way a coagulation RF voltage between them.

After a predetermined time, the unit of control (144) opens the switch (140) and then closes the switch (143), reversing the situation initially described in which is supplied a cutting voltage to the cutting electrode of the electrosurgical instrument (12). Alternating constantly between the two conditions described in this document, the circuit provides a signal of cut waveforms and coagulation ("coag") alternating quickly, to an instrument electrosurgical connected to it. In this way, the instrument you can cut tissue as previously described, while which simultaneously coagulates the tissue to reduce the hemorrhage.

Figure 13 shows an embodiment alternative, in which equal elements are designated by the Same reference numbers. While the layout of the Figure 12 is especially appropriate for a circuit switching in a separate unit of the generator, the arrangement of Figure 13 is more appropriate for a circuit system of switching that is integral with the generator. Instead of those secondary windings (139) and (142) are connected through the generator as in figure 12, in the arrangement of figure 13 the switching elements (140) and (143) through the primary windings (138) and (141) are connected by themselves directly in series through a generator (150). In the figure 13, the second transformer (137) is shown as a simple primary winding (141) and secondary winding (145), without the additional insulation provided by the two transformer stages shown in figure 12. The operation of the circuit Figure 13 is substantially as described with reference to the Figure 12, causing the control unit (144) that the Switches (140) and (143) open and close reciprocally. When the switch (140) is closed, shortening the winding primary (138), a coagulation signal is supplied between output connections (133) and (134). Alternatively, when the Switch (143) is closed, shortening the primary winding (141), a cut signal is supplied between the output connection (135) and connections (133) and (134).

Figure 14A shows a first sequence of mixed output waveform comprising a combination constantly alternating a cut-off waveform (30) and a coagulation waveform (31). The cut waveform (30) is limited to a first voltage threshold (32), while the coagulation waveform (31) is limited to one second (minor) Voltage threshold (33). The cut waveform (30) is supplied during 50% of the work cycle, and the form of coagulation wave (31) is supplied for the remaining 50% of the work cycle. This output waveform sequence produces a tissue effect that cuts and coagulates simultaneously tissue.

Figure 14B shows an alternative sequence mixed output waveform, which again alternates constantly between a cut-off waveform (30) and a form of coagulation wave (31), each limited to thresholds (32) and (33) of tension respectively. However, in the form sequence of output wave of figure 14B, the cut waveform (30) is supplied during 90% of the duty cycle, and the waveform (31) coagulation is supplied for only 10% of the cycle of job. This output waveform sequence cuts more tissue effectively than the waveform of figure 14A, but it has less coagulant effect on the tissue being treated.

The mixed waveforms of Figures 14A and 14B are two default settings for the sequence of mixed output waveform of a generator system according to the present invention, and can be selected or adjusted by the use of a foot switch as shown in the Figure 15, said pedal switch being totally conventional. The foot switch (16) has two pedals (16A) and (16B), being the pedal (16A) normally known as the cutting pedal (and being typically yellow), and the pedal (16B) being known normally as the coagulation pedal (and being typically of color blue). A third pedal (16C) is arranged as a pedal mode selection (this pedal being typically of shape and size different from the other two pedals, and usually black). The operation of the generator system will now be described with reference to these pedals, and to the diagram in figure 16.

If the surgeon is using the instrument electrosurgical connected to the generator only to coagulate tissue, the activation of the coagulation pedal (16B) will cause a 100% waveform is supplied to the instrument coagulation. However, when the surgeon wishes to use the tissue cutting instrument, the cutting pedal (16A) is activated. When the cutting pedal is activated, the generator provides a waveform to the instrument, according to a initial default setting, in this case a waveform 100% coagulation as shown in "A". Custom that successive energy pulses are supplied to the instrument, the waveform changes according to a predetermined evolution, up to that in "(B)" the waveform is 50% cut and 50% of coagulation. Time passed (t1) the waveform has evolved to its final configuration as shown in "(C)", which in this case is a waveform consisting of waveforms of the 90% cut and 10% coagulation. This final configuration will be applied to the instrument until the pedal (16B) is released from cut.

This evolution of the waveform from a initial configuration until a final configuration has several Advantages for the surgeon. First, when you use the Thick tissue cutting instrument, often produced hemorrhage. This cannot always be compensated by coagulating tissue. thick before cutting, since there is a risk that for ensure that the thick tissue is coagulated, part of the tissue It will be "overcoagulated" and dehydrated. The tissue dehydrated is not receptive to RF energy, and therefore the Subsequent tissue cutting will not be effective. In this way, the Hemorrhage is often associated with cutting thick tissue. In In this provision, the instrument maintains an element of coagulation, especially at the beginning of the process. Of this mode, if the surgeon finds bleeding during the cut electrosurgical, the surgeon releases and then reactivates the cutting pedal (16B). This resets the evolution to point "A" in figure 16, with a high degree of coagulation with the initial setup.

Second, the increasing proportion of the Cut waveform ensures that tissue cutting is effective in How much is possible that this happens. Maintain at least one 10% proportion of the coagulation waveform ensures that coagulation continues to occur when the instrument moves to through the tissue.

The time it takes for the generator to evolve from initial configuration to final configuration you can vary depending on the type of instrument connected to the generator, and / or the type of tissue typically treated by such an instrument. He evolution time can be a factory setting, or it can be user adjustable using the pedal (16C) adjustment mode. The evolution time is typically of the order of 7.5 seconds, although under appropriate circumstances they can be used evolution times of only 0.5 seconds or up to 10 seconds.

The evolution time from the configuration initial until final configuration may not necessarily be a uniform evolution as shown in figure 16. By For example, the waveform can remain with a content of 100% coagulation for a predetermined time (for example 1.5 seconds) before evolving to the final configuration of 90% cutting and 10% coagulation. This is the situation shown in the Figure 17. An expert will appreciate that different ones will be possible evolutions from initial configuration to configuration final, depending on the type of operation that is being carried out to cape.

Figures 18 to 22 show a type of alternative instrument that can be used together with the electrosurgical generator previously described. Regarding Figure 18, a bipolar forceps device includes a tubular shaft elongated (101) with a proximal end (102), a distal end (103) and a lumen (104) that extends over the entire length of the tubular element At the proximal end (102) of the tubular element (101) there is a set of handles (105) of scissors type with a first handle (106) and a second handle (107). The second handle (107) can be pivoted with respect to the first, in around the pivot pin (108). In a known design of activation mechanism, the second handle (107) has a plug (109) attached to the top of it, so that the movement of the handle causes a movement corresponding on a sphere (110) supported on a support (111) U-shaped

Mounted on the distal end (103) of the element tubular (101) is the set (112) of forceps jaws, which is shown more specifically in figure 19. The set (112) of jaws comprises a first jaw element (113) and a second jaw element (114), joined together in a manner pivoting by means of an isolated rivet (115). The element of jaw (113) is provided with a cutting electrode (116), isolated with respect to the jaw element (113) by means of an insulator ceramic (117). As shown in Figure 20, three rods rigid (118), (119) and (120) electrically conductive, each covered with a layer of electrical insulation, extend to through the lumen (104) of the tubular element (101). Rods (118), (119) are pivotally connected to the respective jaw elements (113), (114) by rigid connections (121), while the rod (120) is connected by means of a cable (124) (best shown in figure 22) to the electrode (116). The proximal ends of the rods (118), (119) and (120) they extend from the tubular element through the sphere (110) and terminate in a connector (122), by which the device It can be connected to the electrosurgical generator (10).

As shown in Figure 19, the cutting electrode (116) is in the form of an elongated rail, which extends along the length of the jaw element (113). The rail (116) is mounted on the ceramic insulator (117) of way that is isolated from the jaw element (113). He rail (116) is typically 100 microns wide, and protrudes from the ceramic insulator (117) at a distance of approximately  50 microns When the jaw assembly (112) is in its closed position, the rail (116) is received in a recess corresponding longitudinal (123) in the jaw element (114), as best shown in Figure 21. In the recess (123) a compressible strip (127) of material of isolation.

The following will describe in more detail the device operation. When tissue is to be cut, the set (112) of jaws approaches the tissue to be cut, with the set of jaws in their open position and tissue in the tangency line (125) of the jaw assembly. A form of cut-off wave from the electrosurgical generator (10) is supplied through the rod (120) to the electrode (116) of cut, and the forceps device is moved longitudinally in the direction of the arrow shown in figure 22. The fabric that is located between the cutting electrode (116) and one or both elements (113) and (114) jaw is cut by the waveform electrosurgical as the device is transferred longitudinally, thereby forming a cutting line longitudinal in the tissue. The set of jaws is maintained in its open position throughout this process, defining the line of tangency (125) in which the tissue is forced.

The device can also be used for coagulate tissue, in a more conventional way, using the jaw set in its closed position. The set of jaws is closed, capturing tissue between the element of jaw (113) and the jaw element (114). Cutting rail (116) is received in the recess (123) and, without the waveform of Electrosurgical cut described previously, does not have an effect of cut over the tissue between them. A coagulation waveform from the electrosurgical generator (10) is supplied between the elements (113) and (114) of the jaw, through rods (118) and (119). This causes coagulation of the contained tissue Between the jaws

The device can also be used to simultaneously cut and coagulate tissue, using a form of mixed wave as previously described. Like previously, the jaw set is closed, capturing tissue between the jaw element (113) and the element of jaw (114). The surgeon presses the cutting pedal (16B) into the footswitch (16), and a waveform is supplied electrosurgical consisting of the initial configuration (100% of coagulation) to the jaw elements (113) and (114). The shape wave evolves, as previously described, so that an increasing proportion of the waveform of cut, the cut waveform being supplied between the rail (116) cutting and jaws (113) and (114). After a period of default time, the waveform reaches its configuration final (90% cut and 10% coagulation), which continues until it releases the cutting pedal (16B).

Claims (16)

1. Electrosurgical generator system for generate power in radio frequency, which includes:

(i)

a radio frequency output stage that has three or more output connections (48, 49, 50; 133, 134, 135);

(ii)

one or more output power sources of radio frequency coupled to the output stage,

(iii)

an operating driver to cause the system supply power in a combined mode in which a first cut-off RF waveform and a second waveform of RF coagulation are distributed to the output connections, including the controller means to feed the waveforms to the output connections so that the first waveform of RF is distributed among a first pair of the output connections, and the second RF waveform is distributed between a second pair of the output connections,

the arrangement of the system being such that the combined mode is adjustable between several configurations, each configuration having a different proportion of the first and second RF waveforms, characterized in that, in response to an input signal activated by operator, the controller causes that the system supplies an output waveform sequence that begins at a predetermined initial configuration, ends at a predetermined final configuration, and switches between the initial and final configurations according to a predetermined evolution. 2. System according to claim 1, wherein the first cut-off RF waveform is a waveform in the that the radiofrequency output voltage developed through output connections is limited to at least a first predetermined threshold value for cutting or vaporization of tissue, and the second coagulation RF waveform is a waveform in which the radio frequency output voltage developed through the output connections is limited to a second threshold value for coagulation. 3. System according to claim 1 or 2, in the that the combined mode is arranged by the controller running to supply a waveform sequence of mixed output that constantly alternates between the first form of RF wave cut and the second RF waveform of coagulation. 4. System according to claim 3, wherein each of the various configurations has a first cycle of default work of the first RF waveform, and a second predetermined duty cycle of the second waveform RF 5. System according to claim 4, wherein the initial configuration has a second duty cycle that is between 70% and 100% of the total delivered output. 6. System according to claim 5, wherein the initial configuration has a second duty cycle that is between 90% and 100% of the total delivered output. 7. System, according to any of the claims 4 to 6, wherein the final configuration has a first work cycle that is between 70% and 100% of the output Total supplied. 8. System according to claim 7, wherein the final configuration has a first duty cycle that is between 90% and 100% of the total delivered output. 9. System, according to any of the claims 4 to 8, wherein the initial configuration is a waveform that has a first duty cycle that is 100% of the total supplied output, and the final configuration is a form mixed wave that has a second duty cycle that is 90% of Total output provided. 10. System, according to any of the previous claims, wherein the initial configuration default has a combination of waveforms such that the proportion of the second RF waveform is greater than the proportion of the first RF waveform. 11. System, according to any of the previous claims, wherein the final configuration default has a combination of waveforms such that the ratio of the first RF waveform is greater than the proportion of the second RF waveform. 12. System, according to any of the previous claims, wherein the predetermined evolution from the initial configuration to the final configuration is a uniform evolution for a predetermined time. 13. System, according to any of the previous claims, wherein the controller is adapted to supply a sequence of output waveforms supplied in the form of a series of pulses.

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14. System according to claim 13, in the that the pulses are provided at a frequency between 0.5 and 50 Hz 15. System according to claim 14, in the that the impulses are provided at a frequency between 15 and 25 Hz 16. Electrosurgical system comprising:

(i)

a bipolar electrosurgical instrument that includes a handle (105), a set (112) of jaws disposed of so that the manipulation of the handle allows the opposite jaws of the jaw set open and close one with respect to another; having a first of those mentioned opposite jaws at least one first electrode (114) of coagulation; having the other one of the mentioned opposite jaws at least a second coagulation electrode (113); and a cutting electrode (116), the cutting electrode being separated of the second coagulation electrode by means of an element (117) insulator, and

(ii)

an electrosurgical generator apparatus (10) that comprises one or more sources of RF output power, a operating controller to control the generator so that can provide a first cut-off RF waveform to the electrosurgical instrument or a second RF waveform of coagulation to the electrosurgical instrument, and, in a way combined, supply both first and second RF waveforms, the waveforms being fed to the instrument electrosurgical so that, in the combined mode, the form of RF cutoff wave is supplied between electrode (116) of cut and at least one of the first and second electrodes (114, 113) coagulation, and the coagulation RF waveform is supplied between the first and second coagulation electrodes, the combined mode being adjustable between different configurations, each configuration having a different proportion of the first and second RF waveforms,

the arrangement of the apparatus system being generator such that, in response to an input signal activated by operator, the controller causes the generator set to supply a sequence of output waveforms that begins in a default initial configuration, ends in a configuration default end, and switch between initial settings and final according to a predetermined evolution.